Belgic Confession — The Confession originated in the Southern Netherlands, now know as Belgium. Its chief author was Guido de Bres who died a martyr to the faith in the year 1567. He prepared this confession in 1561 to protest against the cruelties of the Roman Catholic government and to prove that the Reformed faith adherents were not rebels. Its text was revised by the Synod of Dort in 1618-1619 and then adopted as one of the Doctrinal Standards of the Reformed Churches.
Heidelberg Catechism — The Catechism originated in Heidelberg, the capital of the German Electorate of the Palatinate, at the request of the Elector, Frederick III in order that the Reformed Faith would gain predominance in the Palatinate. Its authors were Zacharias Ursinus, professor at the Heidelberg University, and Caspar Olevianus, the court preacher and was published in 1563.
Canons of Dort — These are statements of doctrine adopted by the great Reformed Synod of Dort in 1618-1619. In these Canons, the Synod set forth the Reformed doctrine on the following points: unconditional election, limited atonement, total depravity, irresistible grace, and the perseverance of the saints. These canons were developed as a repudiation of the theological errors of Arminius, a theological professor at the University of Leyden.